In all but a few communities throughout North America, community officials rely on door-to-door notification when they have to alert people of emergency situations that demand their immediate attention and action. Generally, however, door-to-door notification is ineffective for a number of reasons. First, it requires a large allocation of human resources in order to reach the many hundreds of thousands of people that may be affected by an emergency situation. Further, the time to recruit and organize the human resources, the danger it may put those human resources in, and the growing distrust of people to strangers that approach their homes, especially at night, all combine to make door-to-door notification ineffective. Numerous news stories of people dying in their sleep from tornadoes, floods, etc., unaware that a dangerous situation existed, provide evidence of how ineffective prior emergency notification systems are and point up the need for an effective community emergency notification system.
In approximately three hundred North American communities, officials presently use a service based on a computerized phone system that calls and delivers a pre-recorded message to all numbers identified to the system provider for notification. The system provider, having secured a contract with a community or private company, has the community or private company provide them with a list of published telephone numbers and a geographic cross reference such as a postal code, or zip-code, so that the list may be narrowed to a specific geographic section of the community.
However, there are a number of problems with such a system. For example, the calls are placed from one or two U.S. locations with all calls having to pass through a local telephone switch. During an emergency, the local switch can be expected to be overloaded already, thereby limiting the probability of a notification call getting through. Additionally, the computerized phone system will send the emergency message as soon as the receiving telephone goes off-hook. Where a peripheral device, such as a common answering machine, is connected to the receiving telephone, the message may be delivered and completed in many instances prior to the answering machine entering into a record mode. In other words, the emergency message may be delivered while the answering machine greeting is being played. Moreover, even if the emergency message is fully recorded on an answering machine, there is no immediate notification of the seriousness of the emergency situation to persons returning to their homes or businesses.
Additionally, in such a system, since the database used by the computerized phone system does not include unlisted numbers, it is incomplete. Also, because of the large number of listing changes that occur daily, the database is typically out of date within a day of being issued and will not include any new listings. Therefore, not all people in an affected area will be notified of an emergency.
Further in using such a computerized phone system, when all the numbers provided have been called, a list of numbers not reached is provided to the municipal authorities for the purpose of door-to-door notification. This list of numbers will include all numbers deactivated since the database was issued, thereby wasting valuable resources sent to reach the people at the registered addresses, and possibly putting these people at risk.
Moreover, in such a system, the capacity of the system is limited by the number of telephone lines available for emergency message notification and by the duration of the emergency message. With a very large geographic area to be notified, or in the event of more than one emergency at a time, the service may not be able to provide the timely delivery of messages needed in response to the emergency situation, such as in the case of a tornado, which offers little time for a warning. Furthermore, in the event of such a rapidly occurring emergency such as a gas leak which is followed by a gas explosion and multi-building fire, becoming an evacuation order, by the time the last messages are being sent, the message may be obsolete and may itself pose a danger.
In such a computerized phone system, the costs include long distance telephone calls made during the emergency. Considering that an emergency may require a number of calls, the annual costs of the system are unpredictable and may exceed budgetary constraints.
Further, the best prior system is only able to provide a delivery rate of about 6,000 calls per hour.
In the case of Canada, the Canadian Government abandoned an attempt to provide emergency notification to all people within a designated area at all times of the day or night in the 1980's because no economical or thorough means to do so could be found. A 1993 provincial and municipal survey suggests that the ability to reach people in the night is a top priority for an emergency broadcast system. However, with no practical means of doing so, the Canadian Government is now implementing a national broadcast system that does not include this ability. Additionally, the problem of effective community, or geographically specific, emergency notification appears to be a problem common to all NATO countries.
Sirens, the preferred method of war-time warnings, continue to be used in some communities. However, because of the high cost of maintenance and the large number of sirens required to reach growing urban populations, sirens are being used less often. Further, the public has become accustomed to sirens and often ignores them.